Array type inference not as good as Tuple?

[tiby312]

Array type inference not as good as Tuple?

I tried this code:

//No error
fn test_tuple() {
 
    let arr=[(0u32,0);2];
    let mut last=None;
    for &(x,y) in arr.iter(){
        if let Some((x,y))=last{
            dbg!(x,y);   
        }
        last=Some((x,y))
    }
}

//Compile time error
fn test_arr() {
 
    let arr=[[0u32,0];2];
    let mut last=None;
    for &[x,y] in arr.iter(){
        if let Some([x,y])=last{
            dbg!(x,y);   
        }
        last=Some([x,y])
    }
}


fn main(){
    test_tuple();
    test_arr();
}

I expected to see this happen: It to compile

Instead, this happened: It didnt compile

Same behavior on stable and nghtly